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Majalah Ilmiah UNIKOM

Vol.10 No. 1


H a l a m a n


The Elevator Group Control System

In the elevator group control system,

hall call

given through buttons on the hall of the

car call

elevator by the passengers. An elevator

group control system has a pair of hall call

up hall call

down hall call

passenger presses a hall call button, an

elevator is selected by the group control

system for the passenger.

The most important task of an elevator

group control system is selecting a suitable

elevator for each passenger’s hall call (up,

down). The selection is made in order to

provide service to every floor in a building, to

minimize the time spent by passengers

waiting for service, to minimize the time

spent by passengers to move from one floor

to another, to serve as many passengers as

possible in a given time and to minimize the

power consumption. The selection method is

hall call assignment method

evaluation function

to achieve the above multiple objectives.

The function is evaluated for each elevator

and the elevator with the smallest function

value is selected. Let

be the

evaluating function for the

-th elevator,

then this function is represented with the

following formula :


function value is evaluated for the




is the estimated arrival

time of the

-th elevator (the waiting time

of the passenger when we assign the


elevator for the new hall call).


calculated by the following formula.

In the above formula, we divide the path


means floors where hall calls and car calls


there are no calls near the floor. So if an

elevator is distant from a hall call or it is

moving opposite to the direction of the hall

call, the probability of that elevator being

assigned to the hall call decreases.

area value

area weight

is higher

when the generated hall call is nearer to the

floors where

-th elevator is going to stop.

The value of

is subtracted to adjust

the usage of energy saving effect and

represents the extent of the adjustment.

is the elevator’s status value. This

value is added to prevent selecting the


elevator if there exists a special kind of call

(VIP call) or the elevator is not running.

The Area-Weight

If elevator

is going to floor


of elevator

for floor

is defined. When

a hall call happens in this area, our

fundamental strategy is to select


for the call. The area represents the range of

floors which can be served easily by that

elevator. The area-weight is the value to

increase the assignment probability for an

elevator which is going toward the floor

where a hall call was generated.

In general, the area is defined in the form

of a trapezoidal as shown in Figure 5. The

Muhammad Aria